Me to: I'm not sure how to exacty apply the FITS calibration frames. Also, the frames seem to introduce some banding noise.
So I have calculated an auto-hotpixel-dark from the lights which removes the hotpixels quite well when subtracted as a raw dark.
Those who can use 16-Bit PNGs as raw darks and like to try it out, can get it here:
https://www.dropbox.com/s/xj00blp3l1...k_raw.png?dl=0